/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: ObjectType.java,v 1.2.4.1 2005/09/12 11:45:54 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler.util;

import com.sun.org.apache.bcel.internal.generic.ALOAD;
import com.sun.org.apache.bcel.internal.generic.ASTORE;
import com.sun.org.apache.bcel.internal.generic.BranchHandle;
import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.GOTO;
import com.sun.org.apache.bcel.internal.generic.IFNULL;
import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
import com.sun.org.apache.bcel.internal.generic.Instruction;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.PUSH;
import com.sun.org.apache.xalan.internal.xsltc.compiler.Constants;
import com.sun.org.apache.xalan.internal.utils.ObjectFactory;

/**
 * @author Todd Miller
 * @author Santiago Pericas-Geertsen
 */
public final class ObjectType extends Type {

  private String _javaClassName = "java.lang.Object";
  private Class _clazz = java.lang.Object.class;

  /**
   * Used to represent a Java Class type such is required to support
   * non-static java functions.
   *
   * @param javaClassName name of the class such as 'com.foo.Processor'
   */
  protected ObjectType(String javaClassName) {
    _javaClassName = javaClassName;

    try {
      _clazz = ObjectFactory.findProviderClass(javaClassName, true);
    } catch (ClassNotFoundException e) {
      _clazz = null;
    }
  }

  protected ObjectType(Class clazz) {
    _clazz = clazz;
    _javaClassName = clazz.getName();
  }

  /**
   * Must return the same value for all ObjectType instances. This is
   * needed in CastExpr to ensure the mapping table is used correctly.
   */
  public int hashCode() {
    return java.lang.Object.class.hashCode();
  }

  public boolean equals(Object obj) {
    return (obj instanceof ObjectType);
  }

  public String getJavaClassName() {
    return _javaClassName;
  }

  public Class getJavaClass() {
    return _clazz;
  }

  public String toString() {
    return _javaClassName;
  }

  public boolean identicalTo(Type other) {
    return this == other;
  }

  public String toSignature() {
    final StringBuffer result = new StringBuffer("L");
    result.append(_javaClassName.replace('.', '/')).append(';');
    return result.toString();
  }

  public com.sun.org.apache.bcel.internal.generic.Type toJCType() {
    return Util.getJCRefType(toSignature());
  }

  /**
   * Translates a void into an object of internal type <code>type</code>.
   * This translation is needed when calling external functions
   * that return void.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      Type type) {
    if (type == Type.String) {
      translateTo(classGen, methodGen, (StringType) type);
    } else {
      ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
          toString(), type.toString());
      classGen.getParser().reportError(Constants.FATAL, err);
    }
  }

  /**
   * Expects an integer on the stack and pushes its string value by calling
   * <code>Integer.toString(int i)</code>.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      StringType type) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();

    il.append(DUP);
    final BranchHandle ifNull = il.append(new IFNULL(null));
    il.append(new INVOKEVIRTUAL(cpg.addMethodref(_javaClassName,
        "toString",
        "()" + STRING_SIG)));
    final BranchHandle gotobh = il.append(new GOTO(null));
    ifNull.setTarget(il.append(POP));
    il.append(new PUSH(cpg, ""));
    gotobh.setTarget(il.append(NOP));
  }

  /**
   * Translates an object of this type to the external (Java) type denoted
   * by <code>clazz</code>. This method is used to translate parameters
   * when external functions are called.
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      Class clazz) {
    if (clazz.isAssignableFrom(_clazz)) {
      methodGen.getInstructionList().append(NOP);
    } else {
      ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
          toString(), clazz.getClass().toString());
      classGen.getParser().reportError(Constants.FATAL, err);
    }
  }

  /**
   * Translates an external Java type into an Object type
   */
  public void translateFrom(ClassGenerator classGen,
      MethodGenerator methodGen, Class clazz) {
    methodGen.getInstructionList().append(NOP);
  }

  public Instruction LOAD(int slot) {
    return new ALOAD(slot);
  }

  public Instruction STORE(int slot) {
    return new ASTORE(slot);
  }
}
